adj. (Of a topology) in which disjoint closed sets can be separated by disjoint neighborhoods

adj. in the default position, set for the most frequently used route.

n. A line or vector that is perpendicular to another line, surface, or plane.

n. A person who is normal, who fits into mainstream society, as opposed to those who live alternative lifestyles.

from the GNU version of the Collaborative International Dictionary of English

adj. According to an established norm, rule, or principle; conformed to a type, standard, or regular form; performing the proper functions; not abnormal; regular; natural; analogical.

adj. According to a square or rule; perpendicular; forming a right angle. Specifically: Of or pertaining to a normal.

adj. Standard; original; exact; typical.

adj. Denoting a solution of such strength that every cubic centimeter contains the same number of milligrams of the element in question as the number of its molecular weight.

adj. Denoting certain hypothetical compounds, as acids from which the real acids are obtained by dehydration; thus, normal sulphuric acid and normal nitric acid are respectively S(OH)6, and N(OH)5.

adj. Denoting that series of hydrocarbons in which no carbon atom is bound to more than two other carbon atoms; Cf. Iso-.

n. Any perpendicular.

n. A straight line or plane drawn from any point of a curve or surface so as to be perpendicular to the curve or surface at that point.

from The Century Dictionary and Cyclopedia

According to a rule, principle, or norm; conforming to established law, order, habit, or usage; conforming with a certain type or standard; not abnormal; regular; natural.

Serving to fix a standard; intended to set the standard: as, a normal school (see below).

In music, standard or typical: as, normal pitch or tone, a pitch or tone of absolute acoustical value, which is used as a standard of comparison. See key, 7, and natural key (under key).

In geometry, perpendicular: noting the position of a straight line drawn at right angles to the tangent-line of a curve, or to the tangent-plane of a surface, at the point of contact.

Synonyms Regular, Ordinary, Normal. That which is regular conforms to rule or habit, and is opposed to that which is irregular, fitful, or exceptional. That which is ordinary is of the usual sort and excites no surprise; it is opposed to the uncommon or the extraordinary. That which is normal conforms or may be figuratively viewed as conforming to nature or the principles of its own constitution: as, the normal action of the heart; the normal operation of social influences; the normal state of the market.

n. In geometry, a perpendicular; the straight line drawn from any point in a curve in its plane at right angles to the tangent at that point; or the straight line drawn from any point in a surface at right angles to the tangent-plane at that point. See cut under binomial.

In chem.:

Of a salt, having all the readily replaceable or basic hydrogen of the corresponding acid replaced by one or more metals or strongly electropositive radicals: distinguished from an acid salt in which this replacement is only partial.

Of a solution for use in volumetric analysis, containing of the dissolved chemical substance the reactive equivalent of 1 gram of hydrogen in 1 liter of the solution at 16° C. See normal solution.

n. The rule; the standard.

n. In biology, a species or race considered as a fixed standard which individual organisms may approach by heredity and from which they may recede by variation.

n. In meteorology, the average of a large number of observed values of any given meteorological element, for example, mean temperature, pressure, or rainfall for any hour of the day, or day of the year. The number of observations must be so large that a second group of the same number would give the same average or normal. The normals for the hours of local mean solar time may be corrected or adjusted so as to become normals for the hours of any other standard of time.

n. In compar. psychol., an untrained or uninjured animal whose behavior is made the standard of reference for the interpretation of the conduct of other, trained or operated animals.

What with being abandoned by my mother as an infant and growing up in a two-hundred-year-old farmhouse in the middle of 148 acres with a nut cake father bless his heart and no neighbors in sight, no relatives, no friends, no TV—the word normal would not apply to any other aspects of my personality.